Digital baseband communication technology is often used in short-distance wired communication. It is convenient for a transmitter to generate a signal and a receiver to analyze a signal using waveforms of bi-level binary digital baseband symbols as communication signals, so as to simplify requirements of performance of hardwire circuits. Common waveforms of bi-level binary digital baseband symbols comprise: Non-Return to Zero (NRZ), Return to Zero (RZ), Manchester, etc. For NRZ, it is hard for a receiver to accurately determine bit number of a data transmitted by a transmitter for a waveform thereof comprises no bit synchronization clock information, which is inapplicable in practice. For RZ, although a bit synchronization clock is contained therein, it is hard for a receiver to extract bit synchronization signals when a comparatively large number of consecutive 0 is contained in a sending data, which is prone to errors. For Manchester, one symbol is divided into two square waves to provide synchronization signals which results in a comparatively low symbol rate under a same signal bandwidth.